Diamanda Gals (born August 29, 1955) is an American-born avant-garde performance artist, vocalist, and composer. Her parents are Greek Orthodox. Gals was born and raised in San Diego, California. She was classically trained in Jazz Piano from an early age, training which reveals itself consistantly throughout all her work. Known for her distinctive, operatic voice, which has an impressive range, Gals has been described as "capable of the most unnerving vocal terror" . Galas often shrieks, howls, and seems to imitate glossolalia in her performances. Her works largely concentrate on the topics of suffering, despair, condemnation, injustice and loss of dignity. Critic Robert Conroy has said that she is 'unquestionably one of the greatest singers America has ever produced', and comparisons are frequently made between her and another soprano of Greek origin Maria Callas.